手性配体的空间结构与产物对映选择性的关系  

The Relationship Between The Stericstructure of 4-Alkyloxycarbonyl-Thiazolidines, 4-Alkyloxycarbonyl-Oxazolidines as Chiral Ligand and The Enantioselectivity of Products

作　　者：关烨第[1] 孟庆林[1] 李越兰[1] 何琰[1] 李之春[2] 

机构地区：[1]北京大学化学与分子工程学院,北京100871 [2]南开大学元素有机化学国家重点实验室,天津300071

出　　处：《化学通报》2003年第1期44-49,54,共7页Chemistry

基　　金：南开大学元素有机国家重点实验室对外开放基金 ( 12 ;13期 )

摘　　要：首次采用 4 烷氧羰基噻唑烷、唑烷作为手性配体 ,诱导烷基锌对醛类的亲核加成反应 ,获得产物是烷基化的醛 ,最高达 90 %ee ,产率 98%的 (S) 二级醇。系统地考察了该类手性配体三维空间结构变化与产物对映选择性的关系 ,当配体 4 位烷氧羰基上的R、2 位R′基和环体上原子X发生变化时都会引起产物 (S) 二级醇的对映选择性发生规律性变化。对五种不同结构的底物醛在同一手性配体催化下 ,诱导烷基锌对醛类的亲核加成反应 ,底物结构变化也会引起 (S)A series of ( R )-2,2-substituted-4-alkyloxycarbonylthiazolidines and ( R )-2,2-substituted-4- alkyloxycarbonyl-oxazolidines and some of amino acid esters as chiral ligand (1～7) were synthesized conveniently from natural L-amino acids and have successfully been used in the enantio-selective addition of diethylzinc to aldehydes reactions.Among them the thiazolidine derivatives 3a～c,4a～c are very efficient catalysts,which showed good enantioselectivity up to 90%ee,yield 98%.We have discussed and studied the relationship between the stericstructure of the chiral ligands 1～7 and the enantioselectivity of reaction to yield ( S )-phenylpropanol,the enantioselectivity is influenced by different structure of the thiazolidine rings and oxazolidines rings and the bulkiness of R in the ester group.Chiral ligands 4c,3c were used in the addition of diethylzinc to some other aldehydes.The reaction products with the selectivity of 68%～88%ee could usually be obtained in satisfied selectivities when aromatic aldehydes were used.While moderate selectivities (52%～56%ee) were obtained with n -heptanalaldehyde was used.The use of the 4-alkyloxycabonyl thiazolidine will encourage further study on the use of easily prepared chiral catalysts in asymmetric catalysis and synthesis from readily available amino acid.

关 键 词：手性配体 空间结构 产物 对映选择性 4-烷氧羰基噻唑烷 E唑烷 醛 不对称加成 烷基锌 亲核加成 

分 类 号：O641.4[理学—物理化学]